The performance of a microscope depends primarily on the performance data and correction quality of the microscope objective being used.
In confocal microscopy, a great deal of value is placed on as perfect a parfocality as possible over an extremely large spectral range of 365 nm to 900 nm. This property being sought should if possible also be combined with the requirement of large objective fields, which is very important as well.
An apochromatically corrected microscope objective with a high aperture, a large object field and apochromatic correction in a wavelength range from ultraviolet to infrared is described in DE 102005027 423 A1, for example. However, water is used in this case as the immersion medium.
Known immersion objectives that use water as known solutions have the disadvantage that the numerical aperture is limited to about 1.2. However, higher numerical apertures and thereby a higher resolution capability require an oil immersion as a necessity.
In DE 102009037743 A1, a high-aperture immersion objective of an oil immersion for confocal applications in microscopy is described, the objective consisting of subsystems comprising three lenses and/or lens groups. In this solution, the disadvantage is that no parfocality is achieved in the UV range from 400 nm to 365 nm.